Posted
by
samzenpuson Wednesday May 12, 2010 @07:50PM
from the moving-to-better-quarters dept.

DarkKnightRadick writes "An undergrad student at the University of Utrecht, Marianne Heida, has found evidence of a supermassive black hole being tossed out of its galaxy. According to the article, the black hole — which has a mass equivalent to one billion suns — is possibly the culmination of two galaxies merging (or colliding, depending on how you like to look at it) and their black holes merging, creating one supermassive beast. The black hole was found using the Chandra Source Catalog (from the Chandra X-Ray Observatory). The direction of the expulsion is also possibly indicative of the direction of rotation of the two black holes as they circled each other before merging."

How exactly is one human brain more complex than an entire human? Or more complex than a dolphin brain? Or more complex than a coral reef, or an aspen grove (or even any large tree)? Or the storm system of Jupiter (or weather in general)? Or the solar atmosphere? Or the Internet? Or the entire galaxy, which coincidently contains lots of brains?

The various connections between the neurons is making up a lot of the complexity I'd think. And a bigger brain does not necessarily mean more of those connections, as the human brain has a lot more of these than the dolphin brain.

But yes, structures containing brains are at least as complex as brains.

Which probably still means we're insignificant. Our intelligence and, most importantly, capabilities are quite limited; and they don't appear to be changing anytime soon. Unless of course you include one possible variant of our potential future descendant(s) - the kind of it(them) that shares mostly just a point of origin, and not much common even "in spirit". The kind we wouldn't even recognise as our progeny; a

I'm no astrophysicist but shouldn't a galactic anchor supermassive black hole tearing ass through it's soon-to-be former host galaxy be dragging a fair amount of material with it and creating a bow shock, much as this runaway star [discovermagazine.com] is doing?

I'm no astrophysicist but shouldn't a galactic anchor supermassive black hole tearing ass through it's soon-to-be former host galaxy be dragging a fair amount of material with it and creating a bow shock, much as this runaway star [discovermagazine.com] is doing?

What do you think is generating the x-rays they're using to spot the black hole?

The accretion disk could account for the X-rays. The reason they were looking for X-rays in the first place was to spot normal black holes.

Right... and accretion disks are created from the material falling into the black hole. If the black hole is heading into intergalactic space and NOT "dragging a fair amount of material with it", where is that material coming from?

I'm no astrophysicist but shouldn't a galactic anchor supermassive black hole tearing ass through it's soon-to-be former host galaxy be dragging a fair amount of material with it and creating a bow shock, much as this runaway star [discovermagazine.com] is doing?

What do you think is generating the x-rays they're using to spot the black hole?

I believe the X-Ray source may be a foreground or background object not associated with the galaxy, and possibly stationary as well. I would expect a super-massive black hole capable of anchoring an entire galaxy that is so off-center would cause some serious deformation to the host galaxy, which is a feature that clearly is not present in the provided image. I also believe the lack of an X-Ray source at the galactic nucleus is not due to the super-massive black hole being removed, but rather simply that

Raising this point causes a random question to pop into my mind. How hard would you have to pull on a star (by passing by it with a strong gravity well, for example) to kill the star?

I guess it's more about the force difference between the force applied to different sides of the star, but I'm curious. If a rift opens up in the side of the star, the high pressure plasma inside has to be pretty eager to escape.

If you did manage to tear a "rift" in the "side" of a star, nothing would really happen. The inside of the star is also the center of gravity of the star. The plasma doesn't want to escape, it is being pulled always towards the center of mass of the star. Your rift would pretty much instantly disappear as the gravity of the star continues to pull on the material around it, the star will pretty quickly turn spherical again.

The only way to destroy a star would be to completely scatter all of its material out over an extremely wide area. Keep in mind, solar systems and their stars are formed by giant disks of dust slowingly being pulled together by their own gravity until they form stellar bodies. So to permanently get rid of the star, you'd have to spread it out over an area larger than it's solar system, or it would just re-form again eventually.

The gravity would be canceled when the rift is created. During which time the "center of gravity" would be a multi-point plot map between the two vastly different gravity wells. By creating the rift it would also create a pull on the surrounding matter giving it a bit of a head start with momentum since the gravity well would effect the entire star not just the side it passes on. Being a sharp drop off, gravity/distance could completely destroy a star by even comming close (cosmic distances). It could pull

No, he got the usage wrong in a different portion of his post. "The gravity well would effect the entire star." Effect is a verb as well as a noun, that means to bring about or create, which is clearly not the intended meaning in this context.

Any object that could tear a hole in a main-sequence star like the sun would probably be a compact star of some sort. See this summary of a Scientific American story from 2002:

When Stars Collide; The Secret Lives of Stars; Special Editions; by Michael Shara; 8 Page(s)

Of all the ways for life on Earth to end, the collision of the sun and another star might well be the most dramatic. If the incoming projectile were a white dwarf--a superdense star that packs the mass of the sun into a body a hundredth the size--the residents of Earth would be treated to quite a fireworks show. The white dwarf would penetrate the sun at hypersonic speed, over 600 kilometers a second, setting up a massive shock wave that would compress and heat the entire sun above thermonuclear ignition temperatures.

It would take only an hour for the white dwarf to smash through, but the damage would be irreversible. The superheated sun would release as much fusion energy in that hour as it normally does in 100 million years. The buildup of pressure would force gas outward at speeds far above escape velocity. Within a few hours the sun would have blown itself apart. Meanwhile the agent of this catastrophe, the white dwarf, would continue blithely on its way--not that we would be around to care about the injustice of it all.

I had read that original story and I recall they described a number of star-star impact scenarios (including black holes with main sequence stars).

Well, my limited understanding is that the (outgoing) pressure inside of an active star is super-huge, and only balanced out by the force of gravity due to scale. If you suddenly redistribute the mass by yanking on it with a big gravity source, it seems to me that a huge amount of pressurized plasma would escape. If it loses enough mass, it could fall below the mass limit of fusion, or below the temperature limit of fusion, or something. I'm not an astrophysicist, though.

Given enough iron thrown into the star center, sooner or later it can't sustain the equilibrium fusion energy agaisnt gravitational energy. Then depending on the size, it can go into various state of death, expansion, supernovae etc... So yeah, there are way to kill a star, but what for ?

I don't recall where I read it but there was an observation a while back of what they belived to be a star in the process of being ripped apart by a black hole. Basically it turns into a long arc of hot gas with a bulge in the middle that aligns with the trajectory of the star around the black hole. The effect was not dissimilar to how comet Schomaker-Levy (sic?) broke up and formed a long streak of debris before smashing into Jupiter. However since the star is entirely made of gas then the streak of debris

I'm sorry, the term is indeed entirely inaccurate, I just assumed people would understand what I meant.

A star has two major forces at the core--gravity and pressure. They are normally in equal balance with each other, which is why it maintains its size. If the mass density of the star changes suddenly, there will be places where the pressure may be higher or lower than the gravity. Or, that was my assumption, and what I meant by "rift". I understand that it has no physically existent surface.

The velocity the black hole is likely moving at isn't going to be a whole lot faster than that of it's surrounding medium, the scale is enormously greater. There probably is a bowshock, but we just can't see it from this distance with the instruments we have.

Also the bowshock is most likely radiating in the xray part of the spectrum.

The only real question I have about this is that the separation between the x-ray source and the center of the galaxy looks to be roughly about 3 arcsec

Things get a little weird when your dealing with general relativity and extreme space-time distortions. Also, space is mostly empty space. Even a black hole of this magnitude isn't going to have that strong of a pull over significant distances. For example, you'd feel only Earth-like acceleration at a distance of 1/10th of a light year. Our nearest stellar neighbor is 4.7 light years away. At that distance the acceleration would be.04 m/s^2.

Unless this thing was going through the dense core of the galaxy there's a pretty good chance it wouldn't be hauling much of anything except for it's old accretion disk.

I'm no astrophysicist but shouldn't a galactic anchor supermassive black hole tearing ass through it's soon-to-be former host galaxy be dragging a fair amount of material with it and creating a bow shock, much as this runaway star [discovermagazine.com] is doing?

Me, either. But... maybe that's how they know it's leaving at "high speed" - the faster it goes (beyond a certain point) the less material it would be dragging behind it, as the gravity waves are passing by too fast to overcome the existing inertia of the nearby material.

Crossing the quickly rotating event horizon of two colliding black holes at the same time. Hmmm... makes me want to create an urban legend about it, so that the Mythbusters will be forced to recreate it someday.

Crossing the "event horizon" isn't really an interesting event in and of itself. It just marks a point of no escape and no return. Granted, if you're getting close enough to the black hole to be anywhere near the event horizon, the tidal stresses might be pretty intense, but the horizon itself is not a solid object and likely somewhat boring.

But wait, the scenario of parent poster gets interesting; especially since with supermassive black holes you wouldn't normally notice crossing the horizon.

Unless...the two horizons are just on the verge of merging, almost touching. And suddenly you find yourself in that space, with almost half of you inside one horizon, and the other almost half - inside the second one.

Well, probably not much different from, say, pulling apart somebody with horses. Extremelly instantenous even, as far as phycics allows...

Of course, that's the average density. If black holes result in singularities or near-singularities, the density in the middle is incredibly high whereas the density near the event horizon is stunningly small. Excepting, of course, if there is some mechanism for convection inside the event horizon (e.g., constituent photons orbit the center instead of becoming part of it).

First things first: Nobody knows if a black hole means the end. There are observations where black holes spew stars. Diving into the very crappy science right now (be warned);String theory: we are trapped into a couple of dimensions, but also gravity. By means of gravity we can escape our universe and go to another one. The universe is flat. Quantum physics imply that our universe should at least be linked to another one, or there are more than two universes in pairs that are double sided. Maybe a black hol

The BBC is a little more skeptical, noting "there are alternative explanations for the bright X-ray source; it could also be a Type IIn supernova, or an ultra-luminous X-ray source (ULX) with an optical counterpart (which could represent several phenomena)."

I might argue that it is an ultra-luminous X-ray source with an optical counterpart that could represent several phenomena, with one of those phenomena being a super-massive black hole being ejected from a galaxy. But hey, that's just me!:)

There was so much power involved in the interaction between those two black holes that millions of apostrophes were flung violently out of the two merging galaxies. One of them landed in the middle of this summary's word "its" and making the editor appear to be an idiot.

The problem with this is that people very frequently say "it's a nice day" (instead of "it is a nice day"). And so it's rather convenient to have a consistent, rule-based way to write that same expression, without confusing anyone about whether or not you meant the term in its possessive form. Contractions are a natural part of language. Writing them down is an unavoidable necessity. So... how helpful that we have a very simple, binary rule. "It's" always means

Hmmm. Let's see... am I the one "editing" one of a handful of summaries that are presented to untold thousands of visitors on a high profile web site every day? Nope! That apostrophe was a typo, anyway. It was a thinko.

Even if there isn't, this is another observation that agrees with the existence of Gravitational Waves, as predicted by General Relativity. If there was such a thing, a merger between two supermassive black holes in a binary system will experience a gravitational wave recoil. In extreme cases, it'll be ejected from the galaxy, much like the one here.

There is tons of weak evidence for gravitational radiation, but if this is true, this is a great

I have seen the videos of the stars at the center of our galaxy whipping around a central unseen mass. These images are compelling. Now I'm going to propose something and I really want someone with a grasp on mechanics to explain why it is impossible:

We know that a mass doesn't actually orbit around another mass, it orbits around the center of gravity of the 2 mass system. So now let's look at 3 masses. They each orbit the center of mass of the 3 mass system. Now let's look at a 400 billion mass sys